Metal WorkingSheet Metal Working

Technology Education Dept.

Bellwood-Antis High School

Mr. Crowell Mr. Mackereth

PROPERTIES OF METALS High Density- Metal is heavy & dense Strength- Metal has strong weight

bearing (load) properties Conductive- Will transmit electricity,

allows for arc & mig welding. Flexible- Can be bent or shaped easily Versatile-Has many uses & applications

COMPOSITION OF METALS BASE METALS- pure metals (contain no

others) & are found on the periodic table. Examples of base metals:

• SILVER COPPER GOLD• IRON LEAD ALUMINUM

ALLOYS- mixtures of 2 or more metals Examples of alloys: STEEL CAST

IRON• BRASS BRONZE SOLDER

COMPOSITION OF METALS FERROUS METALS- metals that contain

IRON (Fe) as one metal in the mixture Examples of ferrous metals: CAST IRON

• STAINLESS STEEL TOOL ALLOYS

NON-FERROUS METALS- any metals (base / alloy) that DO NOT contain IRON

Examples of non-ferrous metals: BRASS• BRONZE BASE METALS except IRON

CARBON STEELS LOW CARBON STEEL- “mild” steel

• Contains 0.05 to 0.3% carbon (steel is an ALLOY)• Soft metal, easy to cut, bend, shape

HIGH CARBON STEEL- “tool” steel• Contains 1.5 to 2.5% carbon• Very hard metal, doesn’t bend, shatters under stress

MEDIUM CARBON STEEL- structural beams• Contains 0.6 to1.0% carbon• Harder than low carbon, but can still be cut & shaped

STEEL FINISHING HOT FINISHED STEEL

• Steel is formed and allowed to cool in open air.

• A BLACK FILM forms on the outside of the steel.

• This film is CARBON that rises to the surface

COLD FINISHED STEEL• Steel is formed, then cooled in controlled

room.• NO FILM forms on the outside of the steel.• This gives the steel a smooth, reflective

surface.• COLD FINISHED is 2X to 3X more expensive

SHEET METALSPROCESSING & COATINGS

SHEET METAL is steel that is pressed by a series of rollers into a flat plate form.• Sheet metal is vulnerable to rust, so it can be

coated by many different materials.

GALVANIZED SHEET METAL• coated on all surfaces with a thin layer of ZINC.

TIN PLATED SHEET METAL (TIN PLATE)• coated on all surfaces with a thin layer of TIN.• Coatings keep sheet metals from rusting and

becoming weak, also keeps metal attractive

PROJECT DEVELOPMENTPlans, Sketches, Drawings

SKETCH- is a ROUGH drawing of a project• NO RULER is used in the drawing (FREEHAND)• NO DIMENSIONS ARE PLACED ON THE DRAWING

PLANS – BLUEPRINTS - “DRAWINGS”• A DETAILED DRAWING of an object or building.• Straightedges are used. Dimensions are labeled.

PATTERN • An object TRACED OUT on top of the metal.

SHEET METAL CUTTING & BENDING METHODS

CUTTING STRAIGHT LINES• Hand Tools- Straight or Combination Tin Snips• Machines- Foot Powered Squaring Shear

CUTTING STRAIGHT LINES• Hand Tools- Circular Pattern Tin Snips• Machines- Table Shear or Punches

BENDING / SHAPING SHEET METAL• BY HAND using a block of wood or table stake• ROLLING MACHINE- makes a cylindrical shape• BOX & PAN BRAKE-makes accurate, straight bends

PROJECT DEVELOPMENTPARALLEL LINE DEVELOPMENT

First, a pair of PARALLEL lines are drawn on the metal.

Then metal is folded, rolled, or cut on these lines

 PARALELL LINE is used to make PRISMS & CYLINDERS.

PROJECT DEVELOPMENTRADIAL LINE DEVELOPMENT First, a fixed point is established on

the metal (can be centered or on edge)

If lines are drawn out & away from the center, then RADIAL LINE can make:

PYRAMIDS If an arc or radius is drawn around the

point, then RADIAL LINE can make: CYLINDERS

PROJECT DEVELOPMENTRECTANGULAR BOX

DEVELOPMENT (1) One set of parallel lines are drawn (2) A second set of parallel lines are

drawn at 90 degrees (perpendicular) to the first set of lines

(3) metal is folded or cut on these lines  It is used to make BOXES & TRAYS .

Your shop project was made using this method.

SOLDERING SHEET METALS

SOLDERING is a process used to seal the seams/joints with solder & a heat source.• A SOLDERING IRON heats the solder alloy.• Soldering metal acts GLUE does on wood pieces• FLUX is applied to the metal to make soldertravel into the seams (prevents surface tension.)• Solder is a mixture (alloy) of LEAD and TIN.• SPECIAL NOTE: Copper water pipes need to be

soldered with LEAD FREE SOLDER to prevent lead from dissolving into water (lead poisoning.)

SOLDERING SHEET METALS HEAT SOURCES PROPANE TORCH

• Used for copper water pipes & other projects• NOT USED for sheet metal (discolors & burns.)

SOLDERING COPPER & OPEN FLAME• Used decades ago by students and industry• Open fires/forges were viewed as DANGEROUS.

ELECTRIC SOLDERING IRON• Uses electricity to heat the copper coated iron.• Safe enough to be used in schools. You will beusing an electric soldering iron for your projects.

CLEANING SOLDERING TOOLS

SOLDERING IRONS are cleaned using a SAL-AMONIAC BLOCK or WIRE BRUSH.

This process removes the oxidized LEAD (a black powdered residue) from the iron

TIN is left on the soldering iron. This process is known as TINNING COPPER

Because lead is poisonous, WASH YOUR HANDS THOUROUGHLY when finished.